58 research outputs found
Flow heterogeneities in the UK Sherwood Sandstone Group: resolving the role of tectonic vs. sedimentary structures
Fluvial and aeolian sedimentary successions represent porous media that can host both groundwater and hydrocarbon resources. Study of their heterogeneities provides a better understanding of both contaminant dispersal in aquifers and techniques for enhancing recovery in oil reservoirs. This research investigates the hydraulic properties of a fluvial succession deposited in a continental rift setting: the Triassic St Bees Sandstone Formation, which represents the basal part of the UK Sherwood Sandstone Group in the eastern Irish Sea Basin. These fluvial deposits have also been compared to the anologous fluvial deposits of the more slowly subsiding shelf-edge basin of the eastern England Shelf aiming to constrain the effect of subsidence rates on preservation of low permeability heterogeneities.
The Triassic deposits of the St Bees Sandstone Formation were investigated from the plug up to the field-scale combining a range of sedimentological, structural, petrophyisical and hydro-geophysical tecniques. The aim of this research is to characterize the impact of sedimentary and tectonic heterogeneities on flow in the continental deposits of the Sherwood Sandstone aquifer assessing the validity of the findings up to reservoir depths.
The hydraulic properties of the St Bees Sandstone Formation are compared with those of other formations of both aeolian and fluvial origin within the Sherwood Sandstone Group, and similar siliclastic formations worldwide to achieve a more general understanding of flow behaviour in siliciclastic sedimentary successions.
In the relatively shallow ( 150m depth) demonstrates that the aquifer has not been subjected to rapid groundwater circulation at these depths; hydraulic conductivity is substantially lower, decreasing from K~10-3 m/day at 150-400 m BGL, to 10-4 m/day down-dip at ~1 km BGL. Pore-scale permeability becomes progressively more dominant with increasing depth. Thus, this sandstone aquifer at ~ 1 km depth approximates the hydraulic properties of analogous hydrocarbon reservoirs which are dominated by intergranular flow. The succession contains a variety of fine-grained and relatively low-permeability units including mudstone beds, interbedded with highly permeable channel deposits. Where present, a higher frequency of occurrence and greater lateral extent of mudstone units impede flow, reducing the field-scale permeability. Zones characterized by higher preservation of mudstone layers also show higher field-scale permeability anisotropy (Kh/Kv) due to a significant reduction of flow perpendicular to these fine-grained heterogeneities. In contrast, normal faults represent preferential flow pathways up to ~1 km depth, due to presence of highly connective open fractures.
Continental successions in rift settings are also characterized by aeolian deposits in the NW Triassic realm, which typically possess higher matrix permeability due to a relatively paucity of integranular clay with respect to fluvial deposits. Thus, reservoir quality rises with increasing content of preserved aeolian sediments due to the dominance of intergranular flow in silicilastic successions buried at depths > ~1 km. Deposits of aeolian-dune versus fluvial origin also exhibit contrasting hydraulic behaviour where intersected by fault zones: normal faults deform aeolian deposits and are dominated by granulation seams which would partially impede flow to production wells in analogous hydrocarbon reservoirs
The treatment of intertrochanteric fracture: a survey on the preferred treatment used by orthopedic surgeons in Campania
n/
Uncovering Predictors of Lipid Goal Attainment in Type 2 Diabetes Outpatients Using Logic Learning Machine: Insights from the AMD Annals and AMD Artificial Intelligence Study Group
Identifying and treating lipid abnormalities is crucial for preventing cardiovascular disease in diabetic patients, yet only two-thirds of patients reach recommended cholesterol levels. Elucidating the factors associated with lipid goal attainment represents an unmet clinical need. To address this knowledge gap, we conducted a real-world analysis of the lipid profiles of 11.252 patients from the Annals of the Italian Association of Medical Diabetologists (AMD) database from 2005 to 2019. We used a Logic Learning Machine (LLM) to extract and classify the most relevant variables predicting the achievement of a low-density lipoprotein cholesterol (LDL-C) value lower than 100 mg/dL (2.60 mmol/L) within two years of the start of lipid-lowering therapy. Our analysis showed that 61.4% of the patients achieved the treatment goal. The LLM model demonstrated good predictive performance, with a precision of 0.78, accuracy of 0.69, recall of 0.70, F1 Score of 0.74, and ROC-AUC of 0.79. The most significant predictors of achieving the treatment goal were LDL-C values at the start of lipid-lowering therapy and their reduction after six months. Other predictors of a greater likelihood of reaching the target included high-density lipoprotein cholesterol, albuminuria, and body mass index at baseline, as well as younger age, male sex, more follow-up visits, no therapy discontinuation, higher Q-score, lower blood glucose and HbA1c levels, and the use of anti-hypertensive medication. At baseline, for each LDL-C range analysed, the LLM model also provided the minimum reduction that needs to be achieved by the next six-month visit to increase the likelihood of reaching the therapeutic goal within two years. These findings could serve as a useful tool to inform therapeutic decisions and to encourage further in-depth analysis and testing
Theoretical and practical aspects of the design and production of synthetic holograms for transmission electron microscopy
Beam shaping-the ability to engineer the phase and the amplitude of massive and massless particles-has long interested scientists working on communication, imaging, and the foundations of quantum mechanics. In light optics, the shaping of electromagnetic waves (photons) can be achieved using techniques that include, but are not limited to, direct manipulation of the beam source (as in X-ray free electron lasers and synchrotrons), deformable mirrors, spatial light modulators, mode converters, and holograms. The recent introduction of holographic masks for electrons provides new possibilities for electron beam shaping. Their fabrication has been made possible by advances in micrometric and nanometric device production using lithography and focused on ion beam patterning. This article provides a tutorial on the generation, production, and analysis of synthetic holograms for transmission electron microscopy. It begins with an introduction to synthetic holograms, outlining why they are useful for beam shaping to study material properties. It then focuses on the fabrication of the required devices from theoretical and experimental perspectives, with examples taken from both simulations and experimental results. Applications of synthetic electron holograms as aberration correctors, electron vortex generators, and spatial mode sorters are then presented
Characterization of a fluvial aquifer at a range of depths and scales: the Triassic St Bees Sandstone Formation, Cumbria, UK
Fluvial sedimentary successions represent porous media that host groundwater and geothermal resources. Additionally, they overlie crystalline rocks hosting nuclear waste repositories in rift settings. The permeability characteristics of an arenaceous fluvial succession, the Triassic St Bees Sandstone Formation in England (UK), are described, from core-plug to well-test scale up to ~1 km depth. Within such lithified successions, dissolution associated with the circulation of meteoric water results in increased permeability (K~10−1–100 m/day) to depths of at least 150 m below ground level (BGL) in aquifer systems that are subject to rapid groundwater circulation. Thus, contaminant transport is likely to occur at relatively high rates. In a deeper investigation (> 150 m depth), where the aquifer has not been subjected to rapid groundwater circulation, well-test-scale hydraulic conductivity is lower, decreasing from K~10−2 m/day at 150–400 m BGL to 10−3 m/day down-dip at ~1 km BGL, where the pore fluid is hypersaline. Here, pore-scale permeability becomes progressively dominant with increasing lithostatic load. Notably, this work investigates a sandstone aquifer of fluvial origin at investigation depths consistent with highly enthalpy geothermal reservoirs (~0.7–1.1 km). At such depths, intergranular flow dominates in unfaulted areas with only minor contribution by bedding plane fractures. However, extensional faults represent preferential flow pathways, due to presence of high connective open fractures. Therefore, such faults may (1) drive nuclear waste contaminants towards the highly permeable shallow (< 150 m BGL) zone of the aquifer, and (2) influence fluid recovery in geothermal fields
Long-term, Real-life, Observational Study in Treating Outpatient Ulcerative Colitis with Golimumab
Background and Aims: Several studies have found Golimumab (GOL) effective and safe in the short-term treatment of ulcerative colitis (UC), but few long-term data are currently available from real world. Our aim was to assess the long-term real-life efficacy and safety of GOL in managing UC outpatients in Italy.
Methods: A retrospective multicenter study assessing consecutive UC outpatients treated with GOL for at least 3-month of follow-up was made. Primary endpoints were the induction and maintenance of remission in UC, defined as Mayo score ≤2. Several secondary endpoints, including clinical response, colectomy rate, steroid free remission and mucosal healing, were also assessed during the follow-up.
Results: One hundred and seventy-eight patients were enrolled and followed up for a median (IQR) time of 9 (3-18) months (mean time follow-up: 33.1±13 months). Clinical remission was achieved in 57 (32.1%) patients: these patients continued with GOL, but only 6 patients (3.4%) were still under clinical remission with GOL at the 42nd month of follow-up. Clinical response occurred in 64 (36.4%) patients; colectomy was performed in 8 (7.8%) patients, all of them having primary failure. Steroid-free remission occurred in 23 (12.9%) patients, and mucosal healing was achieved in 29/89 (32.6%) patients. Adverse events occurred in 14 (7.9%) patients.
Conclusions: Golimumab does not seem able to maintain long-term remission in UC in real life. The safety profile was good
IMPACT-Global Hip Fracture Audit: Nosocomial infection, risk prediction and prognostication, minimum reporting standards and global collaborative audit. Lessons from an international multicentre study of 7,090 patients conducted in 14 nations during the COVID-19 pandemic
Understanding Factors Associated With Psychomotor Subtypes of Delirium in Older Inpatients With Dementia
Inferred fluid flow behaviour in a red-bed fractured aquifer: St Bees Sandstone Formation, UK
Characterizing flow pathways in a sandstone aquifer: tectonic vs sedimentary heterogeneities
- …